Press for making pipes.



' F. GAHLEN. PRESS Fos, MAKlNQ ms. l APPLIATION FILED NOV.6,1912. LSLSBwk @R Panented Jan. 20, 1914 uf Sill "Il 1 the prt-Ss; under the Strainof the work orA "narra" Vr firireia 'FRANZ GAHLELT. OF DUISBURG,GERMANY.

PRESS FOR MAKING PIPES.

Application tiled November 6, 1912.

Specification of Lettera Patent.

Patented Jam 20,1914.

senza No. 729,877.

lio it. known thatl l, ltnxxz (ianLuN, engi* i neer, a Subject ot thellmperur olj (iet-many,

matrix. lNitli auch prennes it was hitherto,

not always poasible to produce pipes with evenly thick wallS; a largeportion of the pressed pipes` had to be scrapped, iin-roaming the enst'.of manu'laet'ure. 'l `he rason 'for this trouble lay in the taet', thatthe mandrel would asaume an eccentric position in the bore oit theImatrix, Such eeeentric position being eanSed by the expansion ot theparteI oit' the intluenee of the heat., by warping ot' the mandrel andlike reasons. As the mandrel 'ill maintain the position imparted to itby the presa plunger, as it is cloaely tilted into the Esame, either.fixed or axially displaeeable, il t obvious that the pipe pressed willhave a wall o t` uneven thielv'ness.

The present invention relates: to a pren-s, by which the ailorementionedtrouble will he avoided. The characteristic `fatture ot' this prees f-onseieta` in the mandrel being arranged So that it can l#wingin theplunger in any direction. ln eonssetpienee ot the mandrel.Q taxing thusable Ato yield in all directions. it will be able to vl'ollow thetendeney of the material to alwaya adjuat the mandrel eoneentrirally.This tendency is a result o'l` the, tolowing; eireumstainea: When themandrel moves into an eeeentrie position, a higher epetfitie 'loree willbe required to it'oree the material through the narrower portion ot theopeningl on the one side, than is re quired to l'oree the materialthrough the opposite wider side ot the openingv ln eon setpienee oi'Asueh ('lili'erenee ln the speeilie Atorre required the mandrel will beurged to 'ward the axis oi the matrix until the speeilie `l'oree theSame all around, that until the mandrel is exactly (lo-axial with thematrix.

'My invention further ronaiats in rigidly guidingr the mandrel duringthe pert'orating ope ation and until its end is properly loated in thedie Orasning, and then releasing the mandrel so that itis 'lree toyield, as above deaeribed. By preventing `further axial or longitudinalnnivement, oli the mandrel aliter itsl end has extended into the di'c, afurther Yfatture ol advantage is attained in that no considerable lengthoi the mandrel is retained within the termed' pipe, and there is, uponwithdrawal ot the nnt'ndrel, no likelihood of injury to either.

ln the aeeompanyiinr dra wiegeI Figure 1 illustrates a mandrel in aneccentric posar tion with renpeetI to the matrix, due to warping, ete.,where the mandrel is rigidly Secured to the plunger an in most knowndevlees.' Figa. 9. and 3 are longitudil'ial views, partly in section, ota` prees, in which the ingot is perforated b y the nn'indrel before thepres-Sing operation proper eonnneneed. Fig'. 3tillust Iates inlongitudinal section a modified lorm ot' the invention.

l'n sueh drawings, n. is the mandrel, b iS the matrix, (l iS the ram`with an exchangeable preise plate all, c in the reeeivin" and is theingrot; g in a eronahead which can be longitmlinally moved toward thepress plunger l1, an l in which the mandrel fr is Secured at its rearend.

The operation ol sueh a prees is aa follows: After the ina-ot has beenintroduced into the, reeeiver, the ram n'. is advanced together with themandrel until the perforatf iner of the ingrat; is eompleted and theprees pla te rl" almost. `tran-liesl the ingrot. This inoment is rhownin Fig. Q. During auch per- `foratien the pressure ot the auxiliarycylinder 'i provided in the plunger z, arts'onthe cronishead .f/ andthereby on the mandrel (i. The latter is: eentered in a short guide laat the trout end ot the ram il. 'l'llilgiiitie is ot a little largerdiameter than the' front end ot the mandrel determining' the Size of thepipe to be pressed. ope ation is eommenetal. the erosshead g iS seeuredin known manner b v .means oi" tlie rods Z, so that the mandrel will notpartielpate in the it'urther travel of the ram (I. The ram d will no\vad vanre. alone, telescope over the mandrel and the guide will leave thetliii'ker part, o'l the mandrel. S'o that during the following pressingoperation it can Ylollow tbel atm-ementioned tendency of the material tomore the mandrel tann'entrieally to the matrix. ln order that themandrel letore the presing i side of the press disk d1.

should oppose this tendency as little as pos` sible, it is secured atits rear end in the crosshead g s0 that it can oscillate therein.

Fig. 3 shows'the press at a given moment during the pressing operation.

At the front end of the ram- (Z, between the ram. and .the press disk Z1a ring m may be provided, Which is radially movable with the mandrel,.and will prevent the material from entering between the ram and. themandrel.l In place ofr such ring,'a ring n` may be provided for the samepurpose, outy Fig. 4, the mandrel will participate in the Whole travelof the ram d. In this case .the crosshead g and then auxiliary cylinderz' are dispensable. The mandrel is secured to the ram only,in`such amanner, that it Will be held -coaxially to the ram during theperforating operati-on,

In the form shown i and, ean"'oscillate during the pressing operation?.l,At-its rear end the mandrel is cen- ,c .tere "in the ram, and at itsfront end in a short guide la, the sami as 4shown in l Figs. 2 and 3.0During the perforatingope'ration the mandrel'will be held in itsposition by until its end extends into the die-opening,

means fcrvpreventing further forward longitudinal movement ofthemandrel, means for rigidly guiding said mandrel during' the perforatingmovement and subsequently releasing it, means for' forcing the metalthrough the die and around the mandrel,

and means permitting the mandrel -to automatically center itself in thedie.

2. .A press for producing tubes, comprising a metal receptacle, a die, aself-centering mandrel, means for lforcing said mandrel through saidreceptacle to perforate the metal and until its end extends'into thedie-opening, means for rigidly guiding said mandrel during theperforating movement and subsequently releasing it, and means forforcing the metal through the die and around the released self-centeringmandrel.

3. A press for producing tubes, comprising a metal receptacle, a die, anoscillatable mandrel, a crosshcad to which said mandrel. is connected bya universal joint, means for forcing and for guiding said mandrelthrough the said receptacle until -its end extends into the die-opening]means for preventing further forward longitudinal movement of themandrel, means for freeing the mandrel from said guiding-means, therebypermitting the mandrel to oscillate, and

means for forcing the -metal through the die` vmeans for further movingsaid plunger to force the metal through the die.

5. A press for producing tubes, comprisin a metal receptacle, an annulardie, a ho low plunger, a crosshead having a mandrel connected thereto bya universal joint, said mandrel extending throughthe opening in theplunger, the Wal-l of said openingbeing contracted at its lower end toform a guiding-surface for an enlarged portion of said plunger, meansfor moving said plunger and mandrel together until theend of the mandrelhas entered the die-opening, means ,for preventing further movement ofthe mandrel, and means for further moving said plunger to force themetal through the die and around the mandrel.

6. A press for producing tubes, comprising a metal receptacle having anannular die, a self-centering mandrel, means for moving said mandrelthrough the receptacle to perforate the metal and enter the die, aplunger 'surrounding said mandrel adapted to-press the metal throughsaid die,

said mandrel projecting loosely through the end of the plunger, and aslidable .metalretaining ring on the face of said plunger and aroundsaid mandrel.

7. A press for producing-tubes, comprising a metal-receptacle having anannular die, an' oscillatable mandrel,means for moving said mandrelthrough said receptacle to perforate the metal, a plunger surroundingsaid mandrel adapted to press the metal through said die when theforward end of the` mandrelfhas reached said die, means for rigidlyymaintaining said mandrel centrallyof said receptacle during theperforating step, means for releasing said mandrel to permit it-'tooscillate Whe-n said plunger is operated, and a metal-retaining ringiitting around said mandrel and slidably en-.

gaging the face of said plunger.

8. A press for producing tubes, compris- .ing the, perforating step andsubsetnently to releasq said mandrel from its rigi position, Saulmandrel projecting loosely throughthe end of saidplungeiyand free tnnscillzxte thm-vin during tln-` inizwinxf :Li'ter Y its release fromwniil rigid punition.

ln testimony wlmi-col I ullix my Awignntlnu in ,plcsenccnt' twowitnesses.

l FRANZ (lillllllilN. Witnesses:

lli-:LEN Nwnn, ALBERT NUFER.

